Tunable Syngas Production from CO2 and H2O in an Aqueous Photoelectrochemical Cell

Syngas, the mixture of CO and H2, is a key feedstock to produce methanol and liquid fuels in industry, yet limited success has been made to develop clean syngas production using renewable solar energy. We demonstrated that syngas with a benchmark turnover number of 1330 and a desirable CO/H2 ratio of 1:2 could be attained from photoelectrochemical CO2 and H2O reduction in an aqueous medium by exploiting the synergistic co‐catalytic effect between Cu and ZnO. The CO/H2 ratio in the syngas products was tuned in a large range between 2:1 and 1:4 with a total unity Faradaic efficiency. Moreover, a high Faradaic efficiency of 70 % for CO was acheived at underpotential of 180 mV, which is the lowest potential ever reported in an aqueous photoelectrochemical cell. It was found that the combination of Cu and ZnO offered complementary chemical properties that lead to special reaction channels not seen in Cu, or ZnO alone.Mixture is better: Syngas (CO+H2) with tunable composition is synthesized from the reduction of CO2 and H2O in an aqueous photoelectrochemcal cell. A turnover number of 1330 and a high Faradaic efficiency of 70 % for CO at underpotential of 180 mV are acheived. The excellent perfomance is attributed to the coupling effects of strong light harvesting of p‐n Si, efficient electron extraction of GaN nanowires, and fast surface reaction kinetics of Cu–ZnO co‐catalysts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134441/1/anie201606424_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134441/2/anie201606424.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134441/3/anie201606424-sup-0001-misc_information.pd

Dr.Bokeh: DiffeRentiable Occlusion-aware Bokeh Rendering

Bokeh is widely used in photography to draw attention to the subject while effectively isolating distractions in the background. Computational methods simulate bokeh effects without relying on a physical camera lens. However, in the realm of digital bokeh synthesis, the two main challenges for bokeh synthesis are color bleeding and partial occlusion at object boundaries. Our primary goal is to overcome these two major challenges using physics principles that define bokeh formation. To achieve this, we propose a novel and accurate filtering-based bokeh rendering equation and a physically-based occlusion-aware bokeh renderer, dubbed Dr.Bokeh, which addresses the aforementioned challenges during the rendering stage without the need of post-processing or data-driven approaches. Our rendering algorithm first preprocesses the input RGBD to obtain a layered scene representation. Dr.Bokeh then takes the layered representation and user-defined lens parameters to render photo-realistic lens blur. By softening non-differentiable operations, we make Dr.Bokeh differentiable such that it can be plugged into a machine-learning framework. We perform quantitative and qualitative evaluations on synthetic and real-world images to validate the effectiveness of the rendering quality and the differentiability of our method. We show Dr.Bokeh not only outperforms state-of-the-art bokeh rendering algorithms in terms of photo-realism but also improves the depth quality from depth-from-defocus

Controllable Shadow Generation Using Pixel Height Maps

Shadows are essential for realistic image compositing. Physics-based shadow rendering methods require 3D geometries, which are not always available. Deep learning-based shadow synthesis methods learn a mapping from the light information to an object's shadow without explicitly modeling the shadow geometry. Still, they lack control and are prone to visual artifacts. We introduce pixel heigh, a novel geometry representation that encodes the correlations between objects, ground, and camera pose. The pixel height can be calculated from 3D geometries, manually annotated on 2D images, and can also be predicted from a single-view RGB image by a supervised approach. It can be used to calculate hard shadows in a 2D image based on the projective geometry, providing precise control of the shadows' direction and shape. Furthermore, we propose a data-driven soft shadow generator to apply softness to a hard shadow based on a softness input parameter. Qualitative and quantitative evaluations demonstrate that the proposed pixel height significantly improves the quality of the shadow generation while allowing for controllability.Comment: 15 pages, 11 figure

Exploring the 100 au Scale Structure of the Protobinary System NGC 2264 CMM3 with ALMA

We have observed the young protostellar system NGC 2264 CMM3 in the 1.3 mm and 2.0 mm bands at a resolution of about 0.1$"$ (70 au) with ALMA. The structures of two distinct components, CMM3A and CMM3B, are resolved in the continuum images of both bands. CMM3A has an elliptical structure extending along the direction almost perpendicular to the known outflow, while CMM3B reveals a round shape. We have fitted two 2D-Gaussian components to the elliptical structure of CMM3A and CMM3B, and have separated the disk and envelope components for each source. The spectral index $\alpha$ between 2.0 mm and 0.8 mm is derived to be 2.4-2.7 and 2.4-2.6 for CMM3A and CMM3B, respectively, indicating the optically thick dust emission and/or the grain growth. A velocity gradient in the disk/envelope direction is detected for CMM3A in the CH$_3$CN, CH$_3$OH, and $^{13}$CH$_3$OH lines detected in the 1.3 mm band, which can be interpreted as the rotation of the disk/envelope system. From this result, the protostellar mass of CMM3A is roughly evaluated to be $0.1- 0.5$ $M_\odot$ by assuming Keplerian rotation. The mass accretion rate is thus estimated to be $5\times10^{-5}$ - 4 $\times$ $10^{-3}$ $M_\odot$ yr$^{-1}$, which is higher than typical mass accretion rate of low-mass protostars. The OCS emission line shows a velocity gradient in both outflow direction and disk/envelope direction. A hint of outflow rotation is found, and the specific angular momentum of the outflow is estimated to be comparable to that of the disk. These results provide us with novel information on the initial stage of a binary/multiple system.Comment: Accepted for publication in the Astrophysical Journal, 21 pages, 12 figure

Coexistence of multiuser entanglement distribution and classical light in optical fiber network with a semiconductor chip

Building communication links among multiple users in a scalable and robust way is a key objective in achieving large-scale quantum networks. In realistic scenario, noise from the coexisting classical light is inevitable and can ultimately disrupt the entanglement. The previous significant fully connected multiuser entanglement distribution experiments are conducted using dark fiber links and there is no explicit relation between the entanglement degradations induced by classical noise and its error rate. Here we fabricate a semiconductor chip with a high figure-of-merit modal overlap to directly generate broadband polarization entanglement. Our monolithic source maintains polarization entanglement fidelity above 96% for 42 nm bandwidth with a brightness of 1.2*10^7 Hz/mW. We perform a continuously working quantum entanglement distribution among three users coexisting with classical light. Under finite-key analysis, we establish secure keys and enable images encryption as well as quantum secret sharing between users. Our work paves the way for practical multiparty quantum communication with integrated photonic architecture compatible with real-world fiber optical communication network

Charge order induced Dirac pockets in the nonsymmorphic crystal TaTe4_4

The interplay between charge order (CO) and nontrivial band topology has spurred tremendous interest in understanding topological excitations beyond the single-particle description. In a quasi-one-dimensional nonsymmorphic crystal TaTe$_4$, the (2a$\times$2b$\times$3c) charge ordered ground state drives the system into a space group where the symmetry indicator features the emergence of Dirac fermions and unconventional double Dirac fermions. Using angle-resolved photoemission spectroscopy and first-principles calculations, we provide evidence of the CO induced Dirac fermion-related bands near the Fermi level. Furthermore, the band folding at the Fermi level is compatible with the new periodicity dictated by the CO, indicating that the electrons near the Fermi level follow the crystalline symmetries needed to host double Dirac fermions in this system.Comment: 9 pages, 4 figures. Second version of the manuscript following the first submission in April 202

Mortality and years of life lost of lung cancer among residents in Pudong New Area of Shanghai from 1995 to 2021

ObjectiveTo investigate the epidemiological traits and potential years of life lost associated with lung cancer mortality among inhabitants of Shanghai's Pudong New Area from 1995 to 2021， in order to serve as a reference for developing intervention approaches.MethodsThe death surveillance system was used to gather statistics on lung cancer deaths. Crude mortality rate （CMR）， standardized mortality rate （SMR）， potential years of life lost （PYLL）， average years of life lost （AYLL）， annual percent change （APC） of the lung cancer deaths were analyzed. The impact of age-structural and non-age-structural factors on changes in lung cancer mortality was quantified using difference decomposition.ResultsThe CMR and SMR of lung cancer among residents in Pudong New Area between 1995 and 2021 were 58.21/105 and 26.75/105， respectively. The CMR of lung cancer increased over the years （APC=1.91%， 95%CI=1.60%‒2.30%； Z=11.487， P<0.001）， and the SMR of lung cancer declined over the years （APC=-1.50%， 95%CI=-1.80%‒-1.20%； Z=-9.006， P<0.001）. Age structure factors and gender factors contributed to the increase of lung cancer mortality， while non-population age structure factors overall appeared to play a protective role which might be related to the improvements in factors such as tobacco control and environmental management. The PYLL of lung cancer was 160 296 person years， the PYLL rate was 2.24‰， and the AYLL was 3.86 years per person.ConclusionAge structure factors are a significant contributor to the disease burden and result in the increase in the crude lung cancer mortality rate of Pudong residents of shanghai. Comprehensive monitoring， preventive， and control methods should be implemented

Construction of Si-Stereogenic Silanols via Enantioselective Pd-Catalyzed C–H Alkenylation

The construction of silicon-stereogenic silanols via the Pd-catalyzed intermolecular C–H alkenylation with the assistance of a commercially available L-pyroglutamic acid has been realized for the first time. Employing the oxime ether as the directing group, the silicon-stereogenic silanol derivatives could be readily prepared with excellent enantioselectivities, featuring a broad substrate scope and good functional group tolerance. Mechanistic studies indicate that L-pyroglutamic acid could stabilize the Pd catalyst and provide excellent chiral induction. Preliminary computational studies unveil the origin of the enantioselectivity in the C–H bond activation step